This invention relates to new and useful improvements in machines for measuring the forces between a belt and pulleys as well as the grinding friction forces between a workpiece and the belt in abrasive belt grinding.
In coated abrasive belt grinding, grinding action occurs between the abrasive grains located on the outside surface of the belt and the workpiece. Required power is transmitted to the belt through the belt backing by the pulley. Because of the grinding workpiece normal force exerted in the grinding contact zone, high concentrated pressure exists in the grinding contact area. This concentrated pressure makes an abrasive grinding belt drive different from an ordinary flat belt drive. The concentrated pressure also makes it difficult to measure the belt force distribution throughout the entire arc of contact.
In the design of an efficient grinding belt power transmission drive, it is important to obtain the normal and tangential belt force distribution. Since the abrasive grinding belt is basically a flat belt with the addition of grinding action between the belt and the workpiece, flat belt power transmission theory can be used in the design of abrasive belt grinding machines. As in flat belt power transmission drives, it is essential in designing an efficient belt drive to obtain a distribution of the normal and tangential belt forces between the belt and pulley along the entire arc of contact.
Measurement of the normal and tangential belt force distributions in abrasive belt grinding has been limited to the grinding contact zone using a conventional photoelastic stress technique. No known apparatus has been introduced to determine the normal and tangential belt force distribution in the entire arc of contact when grinding is performed.
The present invention is directed to new force transducers and apparatus for measuring the normal and tangential belt forces versus angular position in the entire arc of contact, and measuring the grinding friction force between the belt and the workpiece in the study of abrasive belt grinding. In this apparatus, attention has been given to determine the effect of the grinding contact forces on the behavior of the grinding belt as a belt drive rather than on determining the stresses at the grinding contact zone.